1. Field of the Invention
The present invention relates to a microfluidic device including a microchannel, wherein a hydrophobic porous polymer is bonded to walls of the microchannel, and a magnetic bead is bonded to the hydrophobic porous polymer. The present invention further relates to a method of concentrating cells, and extracting and amplifying DNA using the microfluidic device.
2. Description of the Related Art
Microfluidic devices are devices in which at least one inlet and outlet are connected through a microchannel. A microfluidic device is generally used as, for example, a lab-on-a-chip for cell concentrating, cell separating, cell disrupting and amplifying nucleic acid.
A magnetic bead is generally an encapsulated metal oxide particle comprised of a rigid polymeric coating encapsulating the metal oxide particle. The “metal oxide particle” refers to a particle comprising any oxide of a metal or metal alloy having paramagnetic or superparamagnetic properties. A paramagnetic particle refers to a metal oxide particle, which is susceptible to the application of external magnetic fields, yet is unable to maintain a permanent magnetic domain. Stated another way, a paramagnetic particle has inducible magnetic properties. The term “rigid” refers to a polymeric coating that is sufficiently cross linked to the extent that the polymeric coating encapsulates and stabilizes the metal oxide particle within the coating in a manner that the particle remains enclosed therein. Such magnetic beads can be manufactured using known methods in the field. For example, U.S. Pat. Nos. 5,395,688; 5,318,797; and 5,283,079 disclose various magnetic beads.
U.S. Pat. No. 5,834,121 discloses a composite magnetic bead comprising a) a microporous matrix of a first polymer comprising at least one vinyl monomer; and b) a plurality of primary beads, wherein each primary bead comprises a metal oxide having inducible magnetic properties and a coating of a second polymer that comprises at least one vinyl monomer, wherein said coating encapsulates said metal oxide, and wherein said plurality of primary beads is distributed throughout said microporous matrix.
However, a microfluidic device comprising a matrix of a hydrophobic porous polymer covalently bonded to walls of a microchannel, with one or more magnetic beads covalently bonded to the hydrophobic porous polymer, has not been disclosed yet.